The invention relates to a probe support for holding probes which serve for electrical contacting of test substrates in a prober for testing purposes. The invention also relates to a process for testing test substrates in a prober with such a probe support.
In the probers the different test substrates are tested with regard to their electrical properties or are subjected to a special test. In such testing, the test substrates can be in different stages of manufacturing and integration. Thus, tests of semiconductor chips, hybrid components, micromechanical and micro-optical components, and the like are carried out which are in the complete wafer or separated or are already integrated in more or less complex circuits.
For the development and production of electronic components it is necessary to perform the most varied tests and checks at various stages of manufacturing. As is known, for this purpose probers are used which comprise essentially a chuck with a surface for receiving electronic components which are to be tested, the test substrates. The chuck can usually be traversed in the x-direction and the y-direction. The prober furthermore comprises a probe support with probes for electrical contacting of the test substrates. To produce the electrical contact, in addition to the traversability in the x-y plane, which is always defined as that plane in which the receiving surface of the chuck lies, relative movement in the z-direction between the probes and the test substrates is necessary. The required movements in the z-direction can usually be realized by the chuck in connection with a positioning device of the probe support.
The most varied positioning devices for moving the chuck or the probes or the probe support or several of these components, as well as different movement processes following from this, are known with which the relative movements necessary for positioning the probes or the test substrates or both and the relative movements necessary for contacting by the probes can be carried out. With increasing integration density and, associated therewith, minimization of the size of the contact surfaces, the demands on the precision of positioning of probes and test substrates is becoming ever greater, in particular if it is necessary to sequentially traverse to the individual positions of a plurality of test substrates which are disposed in the complete wafer or separated in the form of a grid on the chuck. For this, the wafer or the individual test substrates are disposed on the chuck so that their grid agrees very precisely with the x-direction of motion and the y-direction of motion of the chuck or the probes, that is, the grid and the corresponding directions of motion of the positioning devices are in line. The traversing to the individual positions of the test substrates is then done by incrementally traversing through the grid in the x-direction or the y-direction.
For testing, a definite arrangement of probes, usually corresponding to the density and the size of the contact surfaces and test tips adapted according to the test signal are simultaneously set on the contact surfaces of a test substrate and the test substrate is energized with a signal or a signal is picked up from the test substrate. Then contact is broken off, one traverses to the position of the test substrate coming next in the x-direction or the y-direction, and it is contacted for testing. This structure requires not only the precise alignment of the test substrate on the chuck, but rather also the precise angular alignment of the arrangement of the probes to the contact surfaces to be contacted at the same time.